For me if I hit one of your posts my experience would roughly:
* Wow... that type is small (zoom to 125% - something that I know that the vast majority of users do not know how to do)
* Wow... those lines are still too long for an easy read (zoom to 200% - which gets line length sane for me, but the font size is now huge and killing lots of my vertical real estate)
* God damn that fixed header is annoying and cutting into my already limited vertical real estate as I scroll
* Wow... that type is small (zoom to 125% - something that I know that the vast majority of users do not know how to do)
* Wow... those lines are still too long for an easy read (zoom to 200% - which gets line length sane for me, but the font size is now huge and killing lots of my vertical real estate)
* God damn that fixed header is annoying and cutting into my already limited vertical real estate as I scroll
* Hit close or the readability button.